Page 160 - The Miracle of Electricity in the Body

158 THE MIRACLE OF ELECTRICITY IN THE BODY

Perception of Electrical Signals as Sound

The outer ear collects sounds from the outer world and forwards
them to the middle ear, which reinforces the sound vibrations reaching
it and transmits them to the inner ear. The inner ear then sends them to
the brain by turning them into electrical signals according to their inten-
sity and frequency. After visiting several places in the brain, the mes-
sages are finally transmitted to the hearing center where these signals
are processed and interpreted, and the process of hearing finally takes
place.
One of the most surprising things is the speed at which the 20,000
micro-hairs in the channels in the ear react. The middle channel vibrates
at 256 times a second. The channel immediately above it vibrates at 512
times a second, and the channel above that, at 1,024 times. The micro-
hairs’ efficiency in analyzing such fast vibrations allows us to distin-
guish with great sensitivity among musical notes. This constitutes one of
the most sensitive and rapid reactions in the body.
As the brain resolves the sound vibrations of speech reaching it, it
must convert the sound into syllables, and then into sentences, without

Micro-hairs
Hair cell
Sensory
cortex
Basement
membrane Cochlear
nerve fibers
Sound waves formed by vibrating air molecules affect
the eardrum. The vibrations that reach this membrane
set into operation a mechanism consisting of three
bones, transmitting the vibrations to fluid-filled channels
whose interior is covered in micro-hairs. These react to
pressure differences and permit various signals to form.
By the mercy of God, these signals are interpreted with
great sensitivity in the brain as a tune, the sound of the
wind or a doorbell’s ring. Sound wave